Backend Engineer (Java, Scala, Spark)

🏢 Summary: Backend Engineer role focused on building scalable backend systems, APIs, and data processing solutions for a global developer platform used by millions of users. The position involves working with distributed systems and large datasets in an international environment, with initial on-site work in Malmö followed by relocation to Sweden. Offers competitive B2B rates and the opportunity to contribute end-to-end from architecture discussions to production deployment. 🗂️ Requirements: Commercial experience in backend development, Strong knowledge of Java, Strong knowledge of Scala, Experience with Apache Spark, Experience with distributed systems, Experience building and maintaining APIs, Ability to design scalable backend architectures, Experience with data processing pipelines, Experience with CI/CD processes, Ability to work on-site in Malmö and relocate to Sweden 📃 Skills: Java, Scala, Spark, Apache, DistributedSystems, APIs, CI/CD, Backend, DataProcessing 🏢 Description: Salary: Mid Developer : up to 1120 PLN/MD on B2B Senior Developer : up to 1500 PLN/MD on B2B Work model: hybrid , for the first 3-4 months required 3 days/week on-site in Malmö (Sweden), with travel and accommodation covered by the company, followed by relocation to Sweden with a requirement to work 3-5 days per week from the office, along with a rate evaluation after relocation. Why choose this offer? Opportunity to work on global-scale products used by millions of users worldwide Collaboration within international, cross-functional teams Exposure to modern backend technologies (Scala, Java, Spark) Chance to build scalable APIs and developer-facing tools Impact on end-to-end feature development – from concept to production Work in an environment that values ownership, independence, and collaboration Project You will join a team working on a developer platform powering advanced digital products and services. The role focuses on building scalable backend solutions, APIs, and tools that support large-scale applications and external developers. As a Backend Engineer, you will contribute to designing and implementing distributed systems, processing large datasets, and enabling seamless integration between services. You will collaborate closely with engineering, data, and product teams to deliver high-quality solutions used in a global ecosystem. The role combines hands-on development with active participation in architecture discussions , problem-solving , and cross-team collaboration . Responsibilities you'll have: Design, develop and maintain scalable backend systems and services Build and optimize data processing pipelines using tools such as Apache Spark Develop and maintain APIs and backend components for developer-facing platforms Translate business and technical requirements into robust, high-quality code Collaborate with cross-functional and international teams (engineering, product, data) Participate in architecture discussions and propose improvements to system design Ensure performance, reliability, and scalability of delivered solutions Contribute to code reviews, testing, and CI/CD processes Work both independently and collaboratively to solve complex technical problems Technologies you'll work with Java Scala Apache Spark GIS/Mapping Technologies Distributed systems & data processing API design & backend architecture Client – why choose this particular client from the Jit portfolio? Our client is a leading multinational technology organization with a strong international presence. Serving customers worldwide, it offers a broad range of consumer electronics, software, and digital solutions aimed at enhancing user experience and connectivity. The organization is renowned for its innovative approach and its ability to create a seamless ecosystem that integrates its products and services. About Jit Team The Human Factor of IT - it’s not just a slogan, it’s a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 770 experienced experts , to whom we offer developmental projects, a wide range of benefits, and a proprietary professional development programme. Together with clients from around the world, we create innovative IT solutions delivered by highly specialised and efficient teams. Behind our maxim are also charitable and educational activities. We support schools, universities, and educational institutions by conducting workshops, running educational projects, sponsoring events, and donating learning equipment. We offer internships that help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We also support numerous charitable organisations helping people in need, children, and the elderly. We are a Polish company and we share what we have achieved over more than 15 years of activity. By supporting local initiatives, we contribute to the circulation of good energy.

🏢 Summary: Senior Backend Developer role focused on designing and implementing core components of a high-performance trading platform in a cloud-native, microservices environment. The position involves building low-latency order management and event-driven distributed systems using Java/Kotlin on AWS. You will work within a Scrum team to deliver secure, scalable backend services for financial infrastructure. 🗂️ Requirements: Bachelor’s degree in Computer Science, IT or equivalent experience, 6+ years of experience in Java or Kotlin, Experience with Docker and Kubernetes, Strong knowledge of AWS cloud platform, Experience with CI/CD pipelines and automation, Knowledge of microservices architecture, Experience working with distributed systems, Competence in messaging systems, Experience with distributed caching, Understanding of monitoring and observability tools, English proficiency minimum B2 📃 Skills: Java, Kotlin, Kubernetes, Docker, Jenkins, GitLab, AWS, Microservices, CI/CD, Messaging, Caching, Scrum 🏢 Description: Employer: Swiss IT Company in Banking Infrastructure Rate: 6000 - 7500 Eur net per month Cooperation model: B2B Start date: ASAP Recruitment process:  3 steps (pre - screening, technical interview, technical task) Technology stack: Java or Kotlin, Kubernetes, Docker, Jenkins, Gitlab, AI Tools, AWS Team: 20-person Scrum team responsible for separate microservices We are currently looking for a Senior Backend Developer based in Poland (preferred locations: Wrocław, Poznań or fully remote). In this role, you will contribute to the design and implementation of strategic backend components within a high-performance financial technology platform. You will work on infrastructure responsible for order management, execution logic, smart routing mechanisms, and event-driven business services in a cloud-native environment. This is an opportunity to join a fast-growing, product-driven fintech organisation operating in a technically demanding domain with strong market demand and long-term growth potential. Your role is: -> Designing and implementing new releases of a core trading platform -> Contributing to architecture decisions around: low-latency order management execution algorithm smart order routing event driven and distributed systems -> Engineering and operating distributed services in cloud environments -> Collaborating closely with Product, Engineering Leadership, and cross-functional teams -> Ensuring solutions follow current industry best practices and architectural standards -> Designing with security, authentication and authorization in mind Your skills and experiences: -> Bachelor’s degree in Computer Science, IT or equivalent practical experience -> Experience with container orchestration (Docker and Kubernetes) -> 6+ years of experience in Java and/or Kotlin -> Solid understanding of monitoring, observability and diagnostics tooling -> Strong knowledge of cloud platform AWS -> Experience with CI/CD pipelines and automation -> Knowledge of microservices architecture and the ability to work within a distributed system environment -> Proven competence in messaging systems and distributed caching -> Strong spoken and written English (min B2) Nice to have: + Experience with reactive programming patterns + Strong clean-code mindset and experience with test automation Our client offers: + Great opportunity for personal development in a stable and friendly large multinational company + Frequent company events + Flexible working hours If interested, please apply safely through this portal (application rules are in accordance with GDPR). Employment agency Nr 17138.

🏢 Summary: Full-time hybrid Backend Developer contract focused on modernizing backend services, migrating authentication systems to OAuth, and building Spark-based data migration pipelines. The role involves upgrading Java/Scala ecosystems, automating transformations with GenAI tooling, and extending Scala/Play Framework backends in an English-speaking international environment. 🗂️ Requirements: Production experience with Java, Production experience with Scala, Knowledge of Play Framework internals, Experience with Spark, Knowledge of OAuth authentication patterns, Availability for hybrid work in Krakow, English proficiency 📃 Skills: Java, Scala, Play, Spark, OAuth, GenAI, React, TypeScript, Gradle, CI/CD 🏢 Description: Industry: Technology solutions - consumer electronics, software, streaming Client: global enterprise, Swedish entity Work model: full time, hybrid 3 days/week on-site fromKrakow (Equal Business Park) office Project language: English Onboarding : 3 days in Malmo, Sweden Start: ASAP or 1 week notice ideally / at latest start 27th July 2026 Assignment type: B2B Remuneration: up to 200 PLN/h net + VAT FTE: full-time Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals or Akka. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines.

🏢 Summary: Senior Backend Engineer role for a 3-month modernization project focused on upgrading Java and Scala backend services, migrating authentication systems to OAuth, and building large-scale Spark data pipelines. The position requires hybrid work in Warsaw or Kraków, with a fully covered onboarding period in Sweden. 🗂️ Requirements: 5+ years commercial backend experience, Strong production experience with Java, Strong production experience with Scala, Experience with Play Framework or Akka/Pekko, Hands-on experience with Spark, Experience with OAuth authentication, Professional English proficiency, Availability for 2-week onboarding in Sweden, Hybrid availability in Warsaw or Kraków office 3 days/week 📃 Skills: Java, Scala, Play, Akka, Pekko, Spark, OAuth, React, TypeScript, CI/CD, Gradle 🏢 Description: co.brick talents — powered by AI, powered by people. Senior Backend Engineer (Scala / Java) – 3-Month Project Salary: Up to 175 PLN/h net + VAT (B2B Contract) Location: Hybrid – Warsaw or Kraków ( strictly 3 days/week from the office – non-negotiable) Onboarding: 2 weeks on-site in Malmö, Sweden (fully covered) Project Duration: 3 months Start Date: ASAP/Beginning of August at the ABSOLUTE LATEST About the Client & Project On behalf of our client, an innovative company from the technology sector, we are looking for a Strong Senior Backend Developer to join a short-term, high-impact project. The main goal is to modernize and optimize core backend services, streamline data pipelines, and enhance system security. This is a highly autonomous role requiring a seasoned engineer who can jump straight into a complex ecosystem, utilize automation tools for framework upgrades, and handle heavy data migration tasks. Key Responsibilities Modernize and refactor backend services by upgrading legacy Java and Scala-based frameworks. Leverage automation and modern tooling to expedite code transformations, dependency resolution, and compatibility fixes. Migrate legacy authentication mechanisms across various services to secure, OAuth-based solutions. Consolidate multiple data stores into unified, versioned tables by designing and executing heavy Spark/Java batch pipelines. Requirements Minimum of 5 years of commercial backend experience (7+ years is highly preferred). Deep production experience with Java and Scala . Strong familiarity with Play Framework OR Akka (experience with Akka/Pekko is highly acceptable if you are ready to work with Play environments). Hands-on experience with Spark for complex, heavy data pipeline processing. Solid understanding and practical experience with OAuth authentication patterns. Excellent communication skills with Full Professional English (the project language is 100% English). Full availability for a 2-week onboarding trip to Sweden at the very start of the contract. Nice to Have Basic understanding or exposure to frontend technologies (React / TypeScript). DevOps mindset: familiarity with CI/CD pipelines, Gradle, and scripting. What We Offer A transparent, quick 2-stage recruitment process. An attractive hourly rate with seamless B2B invoicing. An opportunity to work on a high-exposure architectural modernization project for an international client.

🏢 Summary: Senior Backend Engineer role for a 3-month modernization project focused on upgrading Java and Scala backend services, migrating authentication systems to OAuth, and building heavy Spark-based data pipelines. The position requires hybrid work in Warsaw or Kraków with an initial onboarding in Sweden. 🗂️ Requirements: 5+ years commercial backend experience, Production experience with Java, Production experience with Scala, Experience with Play Framework or Akka/Pekko, Hands-on Spark experience, Experience with OAuth authentication, Professional English proficiency, Availability for 2-week onboarding in Sweden, Hybrid availability 3 days/week in Warsaw or Kraków office 📃 Skills: Java, Scala, Play, Akka, Pekko, Spark, OAuth, React, TypeScript, CI/CD, Gradle 🏢 Description: co.brick talents — powered by AI, powered by people. Senior Backend Engineer (Scala / Java) – 3-Month Project Salary: Up to 175 PLN/h net + VAT (B2B Contract) Location: Hybrid – Warsaw or Kraków ( strictly 3 days/week from the office – non-negotiable) Onboarding: 2 weeks on-site in Malmö, Sweden (fully covered) Project Duration: 3 months Start Date: ASAP/Beginning of August at the ABSOLUTE LATEST About the Client & Project On behalf of our client, an innovative company from the technology sector, we are looking for a Strong Senior Backend Developer to join a short-term, high-impact project. The main goal is to modernize and optimize core backend services, streamline data pipelines, and enhance system security. This is a highly autonomous role requiring a seasoned engineer who can jump straight into a complex ecosystem, utilize automation tools for framework upgrades, and handle heavy data migration tasks. Key Responsibilities Modernize and refactor backend services by upgrading legacy Java and Scala-based frameworks. Leverage automation and modern tooling to expedite code transformations, dependency resolution, and compatibility fixes. Migrate legacy authentication mechanisms across various services to secure, OAuth-based solutions. Consolidate multiple data stores into unified, versioned tables by designing and executing heavy Spark/Java batch pipelines. Requirements Minimum of 5 years of commercial backend experience (7+ years is highly preferred). Deep production experience with Java and Scala . Strong familiarity with Play Framework OR Akka (experience with Akka/Pekko is highly acceptable if you are ready to work with Play environments). Hands-on experience with Spark for complex, heavy data pipeline processing. Solid understanding and practical experience with OAuth authentication patterns. Excellent communication skills with Full Professional English (the project language is 100% English). Full availability for a 2-week onboarding trip to Sweden at the very start of the contract. Nice to Have Basic understanding or exposure to frontend technologies (React / TypeScript). DevOps mindset: familiarity with CI/CD pipelines, Gradle, and scripting. What We Offer A transparent, quick 2-stage recruitment process. An attractive hourly rate with seamless B2B invoicing. An opportunity to work on a high-exposure architectural modernization project for an international client.

🏢 Summary: Hybrid Backend Developer role focused on modernizing and optimizing backend services, upgrading core technologies, and improving authentication and data pipelines. The project involves Java/Scala development, Play Framework upgrades, Spark-based batch processing, and OAuth migration. B2B contract with fast recruitment process and onboarding in Sweden. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Familiarity with Play Framework internals, Experience with Spark for pipeline-heavy work, Experience with OAuth-based authentication patterns, Fluent English for project communication 📃 Skills: Java, Scala, Play, Spark, OAuth, JDK, GenAI, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw office. 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : 1 week notice period, August 3rd at the latest. 📝 Contract : B2B > up 195 zl/h. ⚙️ Recruitment process : 1 meeting with the client. ⏳ Duration : > 3 months contracts + extensions. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.

🏢 Summary: Backend Developer role focused on modernizing and optimizing backend services and data pipelines, including migration to newer Java/Scala and Play Framework versions and implementation of OAuth-based authentication. The position involves automation with GenAI tools and Spark-based data migrations in a hybrid work model. B2B contract with onboarding in Sweden and full-time engagement in English. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Experience with Play Framework internals, Experience with Spark for pipeline-heavy work, Experience with OAuth-based authentication patterns, Availability to work hybrid from Warsaw or Cracow office, Availability for 2-week onboarding in Malmo, Sweden, Fluency in English 📃 Skills: Java, Scala, Play, Spark, OAuth, JDK, GenAI, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw OR Cracow office. ⏳ Duration : > 3 months contracts . 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : August 3rd at the latest. 📝 Contract : B2B > up 195 zl/h. ⚙️ Recruitment process : 2 meetings. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details: Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.

🏢 Summary: Senior or Staff Backend Engineer role focused on architecting and scaling AI-native backend systems for a modern accounting platform. The position involves designing distributed services, building high-performance APIs, and establishing engineering standards to support rapid, reliable product delivery. You will work closely with Product, AI, and Operations teams to develop agentic systems and scalable data pipelines. 🗂️ Requirements: 5–10+ years of backend engineering experience, Proven experience designing, building, and operating production backend systems at scale, Strong expertise in API design, Strong expertise in data modelling, Deep understanding of distributed systems trade-offs, Hands-on experience with AWS or GCP in production, Practical experience with CI/CD in high-frequency deployment environments, Experience implementing testing and deployment strategies, Strong knowledge of observability practices, Experience participating in on-call rotations 📃 Skills: TypeScript, Node.js, React, AWS, GCP, Terraform, PostgreSQL, OpenAI, Azure, CI/CD, APIs, DistributedSystems 🏢 Description: ABOUT THE ROLE We're looking for a Senior or Staff Backend Engineer to own and evolve our backend services as we scale. This is a broad, high-impact role — you'll architect new features, build the systems that underpin our core product, and set the engineering standards that shape how the whole team works. The focus is on building a modern, AI-native developer experience. That means working closely with Product, AI, and Operations teams to design agentic systems, distributed data pipelines, and scalable incident response infrastructure — and doing it in a way that lets the team ship with confidence multiple times a day. WHAT YOU'LL WORK ON Architecture and feature design Partner with Product, AI, and Operations teams to architect new features and complex agentic systems. Make clear architectural trade-offs that balance platform, product, and business goals. Backend services and APIs Build and maintain the backend services and APIs that power the core product. Ensure systems are secure, well-tested, and high performance. Distributed systems Design and implement distributed services to orchestrate data pipelines, automate investigations, and enable incident response at scale. Operational excellence Own operational best practices so the team can ship multiple times a day with confidence. Healthy on-call culture and strong observability are part of what you'll build and maintain. Engineering standards Set the bar for writing, communication, and system design across the team. Your influence will shape how a modern AI-native product is built. WHAT WE LOOK FOR 5–10+ years of backend engineering experience A strong track record designing, building, and operating production backend systems at scale. Deep backend fundamentals Expertise in API design, data modelling, and reasoning about distributed systems trade-offs. You understand the nuances, not just the patterns. AWS or GCP hands-on experience Solid understanding of how infrastructure decisions impact application reliability and performance. You've run things in production, not just designed them. CI/CD in practice Practical experience with testing and deployment strategies in high-frequency shipping environments. Observability and on-call maturity A solid grasp of what good observability looks like and how to build healthy on-call practices that don't burn people out. Bonus Experience at an early-stage or scaling startup. Exposure to modern AI and ML systems. Experience shipping product without a dedicated product manager. TECH STACK TypeScript, React, Node.js, AWS, Terraform, PostgreSQL, OpenAI, Azure AI. The team uses GitHub, Slack, Linear, Figma, and Notion day to day. THE TEAM Small, senior, and in-person. The office is in central Wrocław, next to the main train station. The expectation is 4–5 days a week in the office. Relocation support is available for the right candidate. COMPENSATION & BENEFITS Salary $130,000 – $190,000 USD depending on experience, plus competitive equity. Wellness and commute stipend $100 per month. Hardware Premium hardware provided — MacBook Pro and AirPods. Food Daily in-office lunch and dinner. Time off 20 PTO days plus 9 US public holidays. Relocation Support available for candidates relocating to Wrocław.

🏢 Summary: Backend Developer role focused on designing and building scalable, secure microservices and APIs using Java and Spring Boot in a cloud-oriented environment. The position emphasizes strong data modeling, architecture design, and CI/CD-driven delivery within Agile teams. The contractor will develop resilient backend solutions and ensure high code quality and reliability. 🗂️ Requirements: Hands-on experience with API and Microservices development in Java or Spring Boot, Proficiency in Java/J2EE application development, Experience with Spring Framework and Hibernate JPA, Experience building and consuming REST web services, Experience working with XML and JSON, Experience with relational or NoSQL databases (Oracle, PostgreSQL, MongoDB), Experience with CI/CD pipelines and Jenkins, Experience with Docker and Git, Unix proficiency, Experience working in Agile methodologies (Scrum or Kanban) 📃 Skills: Java, Spring, SpringBoot, J2EE, Hibernate, JPA, REST, XML, JSON, Oracle, PostgreSQL, MongoDB, Jenkins, Docker, Git, Unix, CICD, Microservices, Agile, Scrum, Kanban 🏢 Description: Location : Cracow Mode : Hybrid (6 days per month at the office - flexible) Contract : B2B Rate : 160-170 PLN/h Introduction & Summary We are seeking a skilled Backend Developer who possesses a deep knowledge of data modeling and architecture. The ideal candidate should have extensive experience in API development using core Java and Spring Boot, with a strong grasp of security principles and Agile methodologies. The role requires an analytical mindset, capable of designing resilient and scalable solutions while working cross-functionally to foster collaboration and innovation. Main Responsibilities Ensure proper definition and architecture of non-functional requirements in design. Develop and grow skills in designing cloud-based, secure, and adaptable solutions. Build scalable, highly reliable product features through effective software design and implementation. Apply problem-solving and analytical skills to diverse challenges. Interact with cross-functional teams for scalable solution production. Estimate engineering efforts and develop realistic schedules. Identify and resolve complex production issues efficiently. Conduct comprehensive design and code reviews and perform unit testing. Utilize source control and bug tracking systems responsibly. Key Requirements Hands-on experience in API and Microservices development using core Java and/or Spring Boot . Proficient in application development using Java/J2EE and related technologies, including Spring Framework and Hibernate JPA. Experience in developing reusable APIs and consuming web services (REST), as well as processing data formats like XML/JSON. Expert knowledge of Agile/Scrum/Kanban development methodologies and experience with databases (Oracle, Postgre, MongoDB). Extensive knowledge of CI/CD deployment pipelines, including Jenkins, Docker, shell scripting, and GIT with Unix proficiency. Nice to Have Experience in JavaScript frameworks such as ReactJs, Node JS, Angular, and jQuery. Familiarity with JavaScript build tools and dependency management. Experience in creating responsive designs using frameworks like Bootstrap. Knowledge of GCP, GKE, AWS is an advantage. Experience or knowledge in system architecture and solution design. Hands-on experience in Python, Machine Learning, and Data Science.

🏢 Summary: Backend Developer role focused on modernizing and optimizing backend services and data pipelines, including technology upgrades, authentication migration, and automation initiatives. The position involves working with Java/Scala ecosystems, Spark pipelines, and OAuth-based security in a hybrid model with onboarding in Sweden. B2B contract with competitive hourly rate and English as the project language. 🗂️ Requirements: Hands-on experience with production Java services, Hands-on experience with production Scala services, Familiarity with Play Framework internals, Experience with Spark for data pipelines, Experience with OAuth-based authentication patterns, Availability for hybrid work (3 days/week in Warsaw or Cracow), Availability for 2-week onboarding in Malmo, Sweden, Fluent English 📃 Skills: Java, Scala, Play, Spark, OAuth, Gradle, CI/CD, React, TypeScript 🏢 Description: 🌍 Work mode: hybrid –  3 days from the Warsaw OR Cracow office. ⏳ Duration : > 3 months contracts . 🔍 Onboarding : 2 weeks in Malmo, Sweden. ⏰ Start : August 3rd at the latest. 📝 Contract : B2B > up 200 zl/h. ⚙️ Recruitment process : 2 meetings. 📕Project language : English. 💼 Industry : Technology. 💻 Workload : Full time (40 hours per week). Summary: The Backend Developer role is aimed at enhancing and modernizing backend services and pipelines within the organization. This position primarily focuses on improving system performance, ensuring robust authentication mechanisms, and implementing automation to streamline processes. Main Responsibilities: Modernise backend services and pipelines by upgrading to the latest JDK, Scala 3.x, and Play Framework 3.x. Apply GenAI tooling to automate code transformations, dependency resolution, and compatibility fixes, producing reusable tools and documentation. Migrate authentication frameworks from legacy APIs to OAuth-based solutions across various backend services. Replace multiple data stores with a single versioned table, creating Spark/Java batch pipelines for backfill/migration and extending Scala/Play backends. Key Requirements: Hands-on experience with production Java/Scala services . Familiarity with Play Framework internals. Experience with Spark for pipeline-heavy work. Comfortable with OAuth-based authentication patterns. Nice to Have: Familiarity with React/TypeScript. For DevOps-leaning candidates: experience with Gradle, scripting, and CI/CD pipelines. Other Details Tools/Methodologies: Java, Scala, Play Framework, Spark, OAuth.